Which of the following examples demonstrates rolling friction? a. between your shoes and the sidewalk as you walk
b. between your bike tires and the road as you ride
c. between a boat and the water as it sails
d. between two hands being rubbed together
* I’ll give brainliest *!

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.

Aball is fired with an initial velocity of 500 m/s at an angle of 30 degrees above the horizontal across a level field. a. what are the horizontal and vertical components of the initial velocity. b. calculate the maximum height, the time of flight, and the range of the ball.